Alkyl polyglycosides have been known for many years, having been first synthesized in the early 1900 by Emile Fischer. Despite this, the products were of little commercial interest until much later.
U.S. Pat. No. 4,393,203 issued Jul. 12, 1983 to Mao et al, incorporated herein by reference, disclose that long chain fatty alcohols can be removed from alkyl polysaccharide products in thin film evaporators to achieve fatty alcohol levels of less than about 2% without excessive discoloration of the alkyl polysaccharide. This allowed for a more cosmetically acceptable product to be developed that is more surface active. The presence of the free fatty alcohol in the mixture, allows for a more water-soluble product, by removing the water insoluble alcohol.
One of the most significant patents is U.S. Pat. No. 5,003,057 issued Mar. 26, 1991 to McCurry et al incorporated herein by reference, provides for a process for preparing glycosides from a source of saccharide moiety and an alcohol in the presence of a hydrophobic acid catalyst is provided. An example of such a catalyst is dinonylnaphthalenemonosulfonic acid. The use of such catalysts provides a number of process advantages, which includes the reduced production of polar by-products. Preferred glycosides produced by the process are higher alkyl glycosides useful as surfactants.
U.S. Pat. No. 3,598,865 (Lew) discloses the production of higher alkyl (C.8-C25) glycosides from a monosaccharide or source thereof and a higher monohydric alcohol in the presence of a latent solvent (lower alcohols) and an acid catalyst selected from the group consisting of sulfuric acid, hydrochloric acid, phosphoric acid, phosphorous acid, toluenesulfonic acid, and boron trifluoride.
U.S. Pat. No. 3,219,656 (Boettner) discloses a process for producing a higher alkyl glycoside by reacting glucose with methanol in the presence of a macroreticular-structured sulfonic acid resin, anhydrous and in the acid form, to produce methyl glycoside which is reacted without isolation with butanol to form butyl glycoside and which in turn is reacted with a higher alcohol to form a surface active higher alkyl glycoside.
U.S. Pat. No. 3,839,319 (Mansfield) discloses a process for producing alkyl glycosides by direct, acid catalyzed reaction of a higher alcohol and a saccharide. The acid catalysts are mineral acids such as hydrochloric and sulfuric, and sulfonic acid exchange resins
The compounds known before the current invention have been primarily used in industrial applications like detergents for dish wash. This is due in part to inherent drying that occurs when these materials are applied to the skin. Many people, one of which is Cognis, have introduced blends of alkyl polyglycosides and traditional surfactants to overcome these limitations. The blending of other alternative surfactants, while demonstrating a long felt need for improvement in the performance of the product, does not address underlying difficulties in the molecule.
Sugars are well known water soluble materials that do not have any surfactant properties in and of themselves. They are important reactants used to make polymers with alkyl polyglycosides to improve water solubility and improve both foam and detergency.
It will become clear that incorporation of the group with improved water solubility results in shifting the HLB to higher values making a far more valuable surfactant material. Increasing the molecular weight results in improved lower irritation.
U.S. Pat. No. 7,507,399 issued Mar. 24, 2009 to O'Lenick entitled Functionalized polymeric surfactants based upon alkyl polyglycosides teaches a series of multifunctional polyglycosides derivatives that are made by the polymerized by the reaction of 1,3 dichloro isopropanol and polyglycosides, together with a functionalizing agent that contains a sulfate, sulfonate, quaternary nitrogen, or a phosphate group. This patent lacks the critical element of the sugar to make an emulsifier.
All patents referenced above are incorporated herein by reference. None of the patents referenced above either alone or combination teach or suggest the making of the compounds of the present invention, namely combining the sugar with the alkylpolyglycoside and the crosslinker.
The Invention
The present invention relates to the finding that the reaction of alkyl polyglycosides, sugars and the proper additional reagent results in molecules that is an excellent emulsifier. It is most interesting that the maximum amount of glycoside units per alkyl group that can be added using known technology is 1.5. This means that the product is a mixture of mono and di functional product. This product has the remaining fatty alcohol stripped off in an evaporative process. The resulting product is about 70% by weight of a product of a d.p. of 1, about 21% by weight of a product of a d.p. of 2, about 7% by weight of a product having a d.p. of 3, and about 2% by weight of a product that has a d.p. of 4.
We have surprisingly learned that taking the alkyl polyglycosides produced in the commercial process, with its inherent properties to make them emulsifiers even when cross linked polymers, and include functional groups, including alkoxy, sulfate, sulfonate, quaternary and phosphate groups results in a series of products that are much more usable in many applications.